Individual electric signaling apparatus



(ModeL) 2 Sheets-Sheet 1.

. T. N. VAIL.

Individual Electric Signaling Apparatus, No. 242,492. Patented June 7,1881.

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(18164191.) 2 Sheets-Sheet 2.

I T. N. VAIL. Individual Electric Signaling Apparatus. No. 242,492. Patented June 7,1881.

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PATENT THEODORE N. VAIL, OF BOSTON, MASSACHUSETTS.

INDlVlDUAL ELECTRIC SIGNALING APPARATUS.

SPECIFICATION forming, part of Letters Patent No. 242,492, dated June 7, 1881.

Application filed March 5, 1881. (Model) b ill T 0 all whom it may concern:

Be it known that I, THEODORE N. VAIL, a citizen of the United States, residing at Boston, in the county of Sufi'olk and State of Massachusetts, have invented a new and useful Improvement in Individual Electric Signaling Apparatus for Telephone and Telegraph Lines and Systems, of which the following is a specitication.

My invention relates to that class of individual signals in which a train of clock-work normally at rest, but set in motion by the action of the operator at the calling-station, operates to mechanically interposc an obstacle in the path of the bell-hammers, and so control them and prevent them from giving the signals, except at certain predetermined and definite spaces of time, the instant of time being ditl'erent at each instrument in the circuit.

Suchfoilnsol'individualsignalingapparatus as have hitherto been constructed in this class have been arranged to give the signal duringthe short space of time which is appropriated to each instrument, and which,it'there area number of instruments in circuit, must necessarily be limited to a very few seconds, unless the motion of the clock-train be made very slow.

Experience has demonstrated that it frequently happens, owing to the temporary absence or inattention of the person called, that a signal of short duration is not responded to, or that after setting the clocks in motion the operator, being busily occupied, fails to transmit the signal at the proper moment. The result in either case is that it is necessary then to await the completion of the revolution of the time-train, in order that all the clocks may once more be at the starting-point together, to set the clocks again in motion, to await the period at which the desired signal may be given, to ring once more, and possibly fail again to attract the attention of the person required, which obviously necessitates still another repetition, each repetition representing a corresponding loss of time both to the calling-operator and to the station in a centraloffice system who has desired electrical connection.

The object of my invention is the obviation of this defect in practice.

My invention consists in a device whereby the signaling apparatus, after being set in mo trolling device or permit-wheel.

tion by the transmitting-office, can then be stopped at any part of its revolution, and consequently at that part of its revolution which is devoted to the especial bell which is to be rung, and can be maintained in that condition at the will of the operator for an indefinite pe riod of time, during which time the operator may signal the required station at his pleasure without signaling any station except the one required, and without being subjected to the inconvenience of being compelled to call or signal in the circumscribed space of time allotted to each station in a continuous revolution, and to the delay (in case of a failure) incurred by awaiting the completion of the first revolution and the necessary portion of the second.

It consists, also, in the employment, in combination with the above device, of electrical currents which are developed in three different states or conditions, varying in character according to the work required to be done, and t'urnishin g at the will of the operator a current of rapidly-alternating direction, an intermittent current of positive direction or polarity, or a current of negative polarity, thus placing in his hands three distinct qualities of current electricity, each of which may be used to per form a distinct office.

In the accompanying drawings devices are shown which embody this invention; and in these drawings, Figure 1 represents a plan or edge view of the signaling apparatus. Fig. 2 is aside elevation of the same with a portion of the frame removed. Fig. 3 represents a perspective view of the armatures and the con- Figs. 4 and 5 represent detached portions, showing the operation of the arresting and signaling devices. Fig. 6 is a front view of the apparatus, showinga dial divided into a numberotequal spaces corresponding to the number of stations, and an index-hand; and Fig. 7 is a diagrammatic drawing of the electric circuits, showing the connections of the magnetogenerator and the transmitting-keys.

Similar letters refer to similar parts throughout the several views.

In the figures, A is a base-board or bed-plate, of metal, on which is arrai'tged the entire signalin g mechanism, comprising a train of clockwork, L, in a suitable frame, B, the dial I, with the index-finger t, the signaling-bell D, the electro-magnet coils M M, their respective softiron armatures d (1, both pivoted at their centers on the arbor b, the binding-posts P P, and a permanent horseshoe-magnet, E, by which the soft-iron armatures are maintained in a state of induced magnetism or polarization.

To the upper end of the polarized armature d the rods 3 and 2 are attached, the former carrying the bell-hammer p, the latter carrying a pin, 9, the use of which will be hereinafter explained. The armature (1 also, at its upper end, carries an upright rod, 1, to which is attached a horizontal pin,f. To the other end of the same armature d a stifl metallic wire, it, is secured, placed at right angles to the armature. The wire is terminates in a projection, q, engaging with the sloti of a lever, h, which is pivoted at 9', and which is at its upper end provided with a curved extension, r. This extension 12, when advanced by the armature d, engages with the pin 0 of the escapementlever n, which is fastened to the arbor of the escapeinent m, and arrests the motion of the clock-train. When it is withdrawn by the movement of the armature (1 in the opposite direction, it is disengaged from the pin 0, releasing the clock-train and allowing it to resume its motion.

The parts as shown are so arranged that the extension 4), which forms the stopping device, engages the pin 0 on the escapement-lever at or near the end of its oscillating movement, thus leaving it ready to oscillate again when disengaged by removal of the stopping device.

The clock-work is of ordinary construction, and its office is the rotation of an armaturecontrolling wheel or disk, (1, which I will designate the permit-wheel a. The permit-wheel a is fixed upon and rotates with the arbor b and the gear-wheel a, and has projecting from its periphery a rim, 1, which normally engages with the pin g, carried by the rod 2, which is attached to and operated by the armature (1.

By the engagement of the pin 9 with the rim 0' the armature is controlled, its movement prevented, and the bell-h am mer normally held away from the bell, thus preventing the signal from being given.

The rim 1" has a portion cut away, so as to form the space 0, which, when brought by the action of the clock-train opposite to the pin g, permits its release, allowing the bell-hammer to reach the hell and give the signal. The construction of these details isclearly shown in Fig. 3. The position of the space 0 is difl'erent in each apparatus, so that no two spaces are opposite the bell-hammers at the same time.

At one point 011 the gear-wheel a is secured a pin, 0, which, upon reaching the horizontal pinfof the armature-rod 1, is caught by it and detained if the armature d is in such a position as to allow the free movementof the cloclc train. This detention is independent of that caused by the engagement of the lever h with the escapement-lever n; and the armature d is so arranged that when attracted in one direction the lever h is operated, causing the timetrain and the permit-wheel a to be stopped at any point of its revolution, and when attracted in the other direction the rod 1 and pin f are placed in position to stop the clockwork and permit-wheel at the time when the pin 0, in its revolution, reaches the corresponding pin f. This furnishes a unison or zero point, where all the clock-trains in a series may come to rest, so that when set in motion by the removal of the unison-pin], influenced by one movement of the armature d, and the release of the escapement m hymn immediately-succceding opposite movement of the same armature, each clock in the series may start from the same point at the same time.

The flat spring 8 serves to withdraw the armature d and the bell-hammer from the bell after each stroke, answering the purpose of a retractile spring.

The permanent horseshoe-magnet E is placed near the base of the instrument, with its poles opposite and near to the armatures (I 11, giving to one of the armatures a permanent induced magnetism of north polarity and to the other a permanent induced magnetism of south polarity, so that when a current of either direction is transmitted through the electro-magnet coils M M both armatures are afl'ected, but oppositely. \Vhen the upper arm ot'd is attracted to the core of the electro'magnet the lower arm of the armature d is similarly attracted, and vice versa.

The index-hand t revolves on the arbor I) and shows on the dial I, which clock-train in the series is presenting the space c of the permit-wheel to the bell-hammer 12. It forms no part of my invention, and is shown merely for the convenience of reference.

The instrument described above is placed at each station along the line, while at the central office and at any other point or points from which it may be desirable to signal is placed a generator of electricity so disposed and constructed as to transmit a succession of rapidly-alternating positive and negative currents at will. This is shown in diagram by Fig. 7. G is the generator, consisting ot'a Sic mens armature rotated between the poles of a permanent magnet. One end of the armature is insulated and is connected by the spring .10 to earth. The other end, y, has a portion cut away, so that when revolved it makes an intermittent contact with the flat spring a and a permanent contact with the spring as, which constantly presses against its end. K and K are circuit-closing keys of ordinary construction, and S a switch connecting the generator to the line, on which the different instruments are designated by numerals 1 to 8, and which is shown as terminating at earth.

1t is obvious that it the Siemens armature ot' the geueratoris revolved while the keys remain undepressednocurrentissenttoline. Ift-hekey K is depressed, a series of rapidly-alternating positive and negative currents is transmitted. If the rotation be continued and key K is depressed, an intermittent current of a given polarity (we will assume positive) is transmitted to line, because during the period of contact between the spring a and the uncut portion of the arbor g the direction of current remains unchanged, and just before the moment of reversal the circuit is broken by the severance of contact between the arbor y and the spring a, which contact is not renewed until a current of the former direction is again generated. This is also the case when the Siemens armature of the generator G is rotated in the opposite di rection, except that the conditions are reversed, for where a positive current was in the former operation transmitted a negative current will now originate in the coil and be transmitted at the moment when the arbory strikes the spring a, ceasing, as before, at the moinentjust before reversal. 1

I have shown the spacec in each apparatus as being equal to one-eighth of the circumference of the rim 0', which arrangement allows eight stations to a line. This will be a sufficient number, as it has not been found advantageous to exceed the number of five or six.

There is however nothin in the mechanism ofmyapparatus which renders such limitation necessary.

Having described the general features of construction of my apparatus, I will now set forth the mode of operation.

\Ve will assume, for the purpose of illustration, that station 5 is to be signaled- The operator will rotate the crank of the generator G rapidly, turning it in such a manner that the arbor y will make contact with the upper side of the spring a, and pressing at the same time to the key K. This operation sends to the line successive currents of rapidly-alternating polarity, which, entering the electromagnets M M of the station-instruments by the bindingposts I? and leaving them by the binding-post P, cause them to charge and discharge with great rapidity. The armatures (I will consequentl y vibrate, releasing by the first electrical impulse each time-train from its respective unison-pin f, and by the second from the escapement-lock o. The time-trains, no longer held, will all start at the same instant. When, new, the operator perceives by his own instrument that the index-hand t, in its traverse over the dial I, has reached the number of the station desired, which in the present case is 5, the space 0 ol' the permit-wheel a at such station will be opposite the pin 9 of the armaturerod 2, and the bell-hammer, no longer retarded by the rim 1", will be free to strike the bell and give the signal. He will then again rotate the generator in the same direction as before, this time pressing the key K, and an intermittent current of positive polarity will be thereby transmitted over theline, which will cause the electro-magnet M M to attract the armatures d d simultaneously but oppositely, owing to their difi'erent relative positions with regard to the permanent magnet E. Their action will then be as follows: By the first. impulse the armature d is attracted by the lower magnet-coil, M, and repelled by the upper coil, M, and moves on its pivot l, bringing the curved end 1) of the stopping-lever It under the pin 0 of the escapetnent-lever 1;, thereby locking the escapetnent and stopping the clock-train with the space 0 of the permit-wheel at opposite the rod of the bell hammer P. The armature d is attracted by the upper magnet-coil. M, and its hammer, no longer controlled by the rim r of the permit-wheel a, is caused to strike the bell each time that the circuit is closed by the arbor y and the spring ti ot' the generater G, while at each intermission it is drawn back by the retractile spring 8. and thus caused to ive a continuous signal.

The lockirig-armature dis not provided with a retracting-spring, and consequently remains drawn to that pole of the electro-magnet to which it was last attracted until released by a current of opposite polarity. The apparatus may be maintained in this condition as long as desirable, thus obviating, in case the sta tion fails at once to respond, the, necessity of awaiting the completion of the revolution and a portion of a second before another signal could be given.

When the station called responds it is connected to the desired point for conversation, and upon the conclusion of the conversation the normal condition of the apparatuses is restored in the following manner: the operator will again press the key K and revolve the armature of the generator G, but in the opposite direction, so that the arbor y will now in its revolution strike the lower side of the spring a. As thearinature is now revolved in an opposite direction, the currents itdevelops will be produced in the reverse order, a negative current originating in the coil and flowing to line at the moment that contact is made with the spring a. The action of the armatures d d is now reversed. The upper end of d is drawn to the core of the electro-magnet M, placing the pinfin a position to engage with the pin 6 of the wheel a on its arrival at that point. The lower end of the armature d is repelled from the core of the coil Mand unlocks the escapement, permitting the clock-train to complete its revolution, while the upper end of the armature d is simultaneously repelled, withdrawing its hammer from the bell and retiring the pin g behind the rim 1' of the permitwheel, where it is retained.

It is to be understood that the telephone transmitter and receiver are at each office to be connected in the usual manner.

I may substitute a galvanic battery and a reversing or pole-changin g key for the magneto-generator which I have described.

It is obvious that the starting of the timetrain from zero could be effected by a single Lil positive followed by asingle negative impulse; but it is preferred to use a series or succession of impulses as being more certain to cause the simultaneous starting of the several trains. A steady current of proper polarity could also he used to start the trains after they have been stopped to give a signal at any station. An intermittent current, however, answers quite as well, and as the commutator apparatus of a magneto-generator for producing such a current is simpler and less complicated than a commutator for transforming the regular alternating current of a magneto-machine to a steady current of given polarity, such a generator is represented.

Having now fully described my said invention and the manner in which the same is or may be carried into effect, I would observe, in conclusion, that although I have shown and described an electromagnetic stopping device combined with a clock-train so as to act upon a mechanical escapement which controls said train, and which may be of any ordinary or suitable construction, and have also shown the stoppingdevice so arranged as to stop the escapement-lever or oscillating governing; portion of the escapement at or near the end of its oscillating movement, I reserve the same for a separate application, and make herein no claim thereto; but

WhatI do claim, and desire to secure by Letters Patent, is-

1. In an individual signalinginstrument having its ringing-armature mechanically controlled by a permit-wheel rotated by a locktrain and adapted to release the armature atter a predetermined interval of time, meehanism, substantially as described, for arresting the lIiOVQlllCllt of the clock-train at any point of its revolution and at any time, as and for the purpose specified.

2. The combination, in an electric signaling apparatus, of a train of clock-work normally at rest and a permit-wheel driven by said clock-work, and, except at one period of its revolution, controlling a bell-hammer, with a locking device adapted to arrest the said clocktrain at the time when the bell-hammer is re leased from the control of the permit-wheel, for the purpose specified.

3. In an electric signaling apparatus, the combination of a clock-train normally at rest, a permitwheel driven by said clock-train and mechanically controlling a bell-hammer, with a locking device and unison, both operated by the same polarized armature, and so arranged that when the unison is thrown oti the locking device is by the same movement applied, and that when the locking device is rendered inoperative the unisou is restored, in the manner and for the purpose specified.

4. lnanindividualsignaling-instrument, the combination of the permit-wheel a the clocktrain L to drive the same, the bellhammer armature d, the electro-magnet M M, and the permanent magnetE with the second polarized armature, d, the locking-lever h, the escapement-pin 0, and the unison device ef, as and for the purpose specified.

5. In a telephonic circuit, a series of signaling-instruments, each provided with the permit-wheel a, the clock-train L to drive the same, the bell-hammer polarized armature d, the electro-magnet M M, and the permanent magnet E, in combination with the second polarized armature, d, the locking-lever h, the escapement pin 0, and the unison device of.

6. The hereinbeforedescribed method of electric signaling, consisting in the employment, in combination with a series of individual signaling instruments, each having an armatlire-controlling device driven by a train of clock work which is normally at rest, of electric currents or pulsations ot' rapidly-alternating direction or polarity, of intermittent currents or pulsations of positive polarity, and of currents of negative polarity, in regular succession, for the purpose specified.

THEO. N. VAIL.

' Witnesses:

WM. 13. Ross, GEo. WILLIs PIERCE. 

